Slow-motion attachment for microscopes



(N0 Mod 1.1 1

t e t H. G. SEDGWIGK.

SLOW MOTION ATTACHMENT FOR MIGROSGOTES; No. 528,211. 1 Patented Oct.30', 1894.

NITED STATES PATENT OFFICE.

HIRAM G. SEDGWIOK, OF NASHVILLE, TENNESSEE.

SLOW-MOTION ATTACHMENT FOR MICROSCOPES SFECIFIOATION forming part ofLetters Patent No. 528,211, dated October 30, 1894.

' Application filed February 10,1894. Serial No. 499,788. (No model.)

To all whom it may concern.-

Be it known that 1, HIRAM G. SEDGWICK, a citizen of the United States,residing at Nashville, in the county of Davidson and State of Tennessee,have invented certain new and useful Improvements in Slow-MotionAttachments for Microscopes and other Instruments, of which thefollowing is a specification, reference being had therein to theaccompanying drawings.

This invention relates to' a slow-motion attachment for use onmicroscopes and other instruments using or requiring rack-anfl-pinionadjusting devices, the essential object of the invention being toprovide a simple and inexpensive attachment thatrmay be readily attachedto and detached from the pinionshaft without in the least mutilating anyof the parts or changing their construction.

The device is adapted for attachment to the pinion-shaft that is usedfor effecting the coarse motion. It is attached on one of the projectingends of the shaft, outside of the instrument, whereby it maybe readilyat tached to all the compound microscopes now in use without mutilatingthem or changing their construction or taking them apart, and thiswhether they be provided with otherfine adjustments or not.

The attachment will be best understood by describing the preferredconstruction; but I wish it distinctly understood that I donot confinemyself to the construction. and arran gement herein shown and describedas the same may be varied greatly without departing from the scope ofthe invention in the least.

In the drawings. Figure 1 is a transverse sectional view showing myattachment ap-- plied to a microscope; Fig. 2, a transverse section online 2-2 of Fig. 1, this view being slightly enlarged; Figs. 3 and 4.-,detail views; and Figs. 5, 6 and 7 detail sections showing a slightlymodified form of spiral pinion.

Referring to the drawings by numerals, 1'

usual frame and carrying at its ends the usual milled operating heads 6.

On the shaft 4, between one of the milledheads and the adjacent face ofarm 5, is mounted the attachment, which consists es- ;sentially of apinion '7 provided with external spiral ribs or threads and mounted onthe shaft in such a manner as tohave only africtional engagementtherewith, whereby the shaft and pinion may revolve independently or inunison. To obtain this frictional engagement in the simplest manner thepinion is split lengthwise on one side to allow it to be expandedslightly and slipped over the end of the shaft, the width of the slitbeing just sufiicient to cause it to hug the shaft with the desiredfriction and at the same time without materially mutilating the spiralribs. Working on this spir'aLpinion is an endwisemovable sleeve or tube8, which is internally ribbed to correspond to the spiral ribs on thepinion and is externally screw-threaded at a suitable pitch. To preventthis tube 8 from rotating and at the same time permit it to freelyslide'endwise, it has one or more longitudinal grooves. or ways out inits exterior in which work stationary keys 9, which project outhorizontally from a plate 10 secured by screws, rigidly but removably,to the side of the microscope or other instrument, the ends of said keysbeing preferably connected by a ring 11.

To slide the tube 8 back and forth on the keys, a tube 12 is fitted overit, this tube being internally threaded to correspond with the threadson said tube 8 and being also provided with a milled operating-head 13,which latteris preferablya trifle larger than the adjacentoperating-head on the main shaft. The inner end of the tube 12 fits overan annular flange 14 on plate 10 and its outer end fits snugly within astationary cap 15, whereby the tube is not only kept true but is alsopre vented from being thrown by the screw against the adjacent milledhead 6. The cap 15 is slipped over the shaft and is secured rigidly tothe ends of the keys, or ring as shown.

To rapidly and. coarsely adjust the tube of the microscope or otherinstrument, theheads 6 are revolved in the usualmanner. During theoperation of coarsely adjustingthe tube by said heads the fineadjustment parts all remain inert, the pinion-shaft being permitted torotate independently of the spiral pinion by reason of the frictionalengagement therewith and the spiral-pinion itself being prevented fromrotating by being interlocked with the non-rotatable sleeve; but whenthe head 13 is rotated to effect the fine adjustment of the microscopetube, the threads on the interior of the outer tube 12, engaging withthe threads on tube 8, cause the same to move endwise on the'keys, andthis endwise movement of the non-rotatable part 8 imparts a slightrotative movement to the pinion shaft through the medium of thespiral-pinion,this pinion gripping the shaft with sufficient tightnessto positively rotate it. Thus it will be seen that the slow-motion partsare only operated when the power is applied to the head 13, thefastmotion parts operating precisely in the same way as ususl and whollyindependently.

The spiral-pinion or twisted-gear 7 may contain any number of teeth fromone upward, according to the degree of accuracy desired. As shown inFig. 5 two teeth or ribs only are employed, two spirally curved groovesbeing formed in the interior of the endwise movable part to engage saidribs; but where great accuracy is required, the ribs will be disposedentirely around the pinion as in Fig. 2, as in that case the ribs on oneside counteract or take up the loose motion on the opposite side, as isapparent.

The advantages of this invention over prior devices of its kind areobvious to any one skilled in the art. I-Ieretot'ore, slow-motions havenot been made in the form of an attachment, attachable and detachable atwill, but have always been made permanent parts of the microscope orother instruments, having been made at the time the instruments weremade, and instruments not provided with the slow-motions had to be sentto the shop and dismantled to have them put on. Then again theslow-motions heretofore used have been too expensive to be put on anybut the finer machines. These serious draw backs have been longrecognized by instrument makers and many attempts have been made toobviate them without material success; but it is believed the presentinvention overcomes said objections, since it may be readily attached toany instrument usinga rackbar and pinion without mutilating ordismantling the instrument and by any person of ordinary intelligence.It will be seen that the device is adapted for attachment directly tothe coarse-motion shaft in the space that usually exists on allinstruments between the side of the instrument and the usual milledhead.

To attach the device it is simply necessary to remove one of themilled-heads and slip the parts of the device on the shaft and thenreplace the milled-head. Of course,a couple of small screw-holes must bemade in the instrument for the reception of the securingscrews. Thus itwill be seen that the application of this device to any of theinstruments now in use-=whether they be provided with other morecomplicated slow-motions or not-involves but a small expense and butlittle trouble.

Besides the advantages of simplicity and general applicability, thusobtaining the slow-motion through the medium of the same shaft andpinion that effects the fast-motion it has other advantages perhaps moreimportant. In the most practicaldevices heretofore in use, theslow-motion has generally been obtained by means of a double-slidearrangement and micrometer screws,as is well known, but this arrangementof two slides is defective for use with high-power objectives for thesimple reason that it is a practical impossibility to obtain perfectparallelity. of the working-faces of the slides, in consequence of whichthe object is frequently thrown or shifted about the field when theslow-motion is resorted to. This "side or upwardthrust, as it is called,is more nearly obviated by using but one sliding surface and effectingboth the course and fine adjustment of the tube through the singlepinion, as is evident.

I have found in practice that a higher degree of accuracy can beobtained with my simple device than can be obtained with the expensivecompound-slide devices heretofore used. It will be seen that simply byincreasing or diminishing the pitch of the threads on the sleeves andthe spiral-ribs on the pinion, almost any degree of fineness andprecision in slow-motion may be obtained, according to the character ofthe instrument.

It will be understood that this. attachment is applicable to instrumentsother than microscopes. For instance, it may be used on telescopes,photographic cameras, stereopticons, andother instruments whererack-andpinion movements are used and a slow-motion is desired. It willtherefore be understood that wherever I use the term instrument in theclaims and in the specification I mean any instrument to which thedevice is applicable.

Having thus fully described my invention, what I claim is- 1. In aslow-motion attachment for microscopes and other instruments, thecombination of the rack-bar and pinion and the shaft carrying thepinion, another pinion mounted on the shaft, a non-rotatable partengaging the latter pinion and adapted to rotate it, and means forimparting an endwise movement to said non-rotatable part, substantiallyas described.

2. In a slow-motion attachment for instruments, the combination of therack-bar and pinion and shaft, a spirally-ribbed pinion on said shaft, apart embracing the said pinion and provided with internal teeth engagingsaid spiral ribs, and means for moving said part, substantially asdescribed,

3. In a slow-motion for instruments, the combination of a rack-bar andpinion, ashaft carrying said pinion and provided with means forimparting the coarse-motion, another pinion mounted on said shaft andadapted to rotate with or independently of it, and means for rotatingsaid pinion, whereby both the coarse and fine adjustments are efiectedthrough the same shaft and pinion, substantially as described.

4. The combination of a rack bar, a pinion engaging the same, a shaftcarrying said pinion, means on the shaft for imparting the coarsemotion, and slow-motion devices attached directly to said shaft, saiddevices consisting essentially of a pinion mounted directly on the shaftand means for rotating said pinion, whereby the coarse motion and theslow motion may be imparted to the rackbar through the same rack andpinion and shaft substantially as described.

5. The combination of a rack-bar and pinion, a shaft, carrying saidpinion and also means for imparting the coarse motion, and aslow-motionattachment applied directly on said shaft and adapted to rotate it, saidattachment consisting essentially of a pinion having a frictionalengagement with the shaft for the purpose described and means forrotating said pinion and looking it against rotation when the coarsemotion is used, sub stantially as described.

6. The combination of arack-bar and pinion and shaft and a slow-motionattachment consisting essentially of a slitted pinion having africtional engagement with the shaft, and. means for rotating the pinionto obtain a fine adjustment, substantially as described.

7. The combination with a rack-bar and pinion, a shaft carrying thepinion and also means for imparting the coarse motion, and a slow-motionattachment consisting essentially of a spirally ribbed pinion mounted onthe shaft, an endwise movable part engaging the pinion and adapted torotate it, and means for moving said endwise movable part, substantially as described.

8. The combination of a coarse-motion shaft and a slow-motion attachmenttherefor, consisting essentially of a spirally ribbed pinion mounted onthe shaft and adapted to rotate with or independently of it, anon-rotatable part provided with corresponding internal ribs or grooves,and means for moving the latter part, substantially as described.

9. Thecombination ofacoarse-motion shaft, a slow-motion attachmentconsisting essen tially of a pinion mounted directly on the shaftand'adapted to rotate with or independently of it, an endwise movablepart engaging said pinion and adapted to rotateit, said part beingscrew-threaded externally, and an external sleeve internally threaded toengage said endwise movable part, substantially as described.

10. The combination of the coarse-motion shaft and means for rotatingit, a slow-motion attachment consisting of a pinion or sleeve mounteddirectly on said shaft, an endwise movable part engaging said pinion andthreaded externally, key-ways engaging said non'rotatable part, a sleeveembracing said non-rotatable part and carrying an operating head,substantially as described.

11. The combination with the coarse-motion shaft and means for rotatingit, a slow motion attachment consisting of a pinion applied directly tothe shaft and provided with one or more spiral grooves, a tube or sleeveembracing said pinion and engaging its spiral ribs and being externallythreaded, key-ways engaging said tube and preventing it rotating, anexternal sleeve threaded internally and engaging said tube, and a stopcap supported by said key-ways, substantially as described.

12. The combination with a microscope or other instrument carrying aslidable bar, a shaft journaled in the instrument and carrying a pinionengaging said bar, and means carried by the shaft for imparting coarsemotion thereto, of a slow-motion attachment mounted directly on saidshaft, whereby the coarse motion and the slow-motion may be imparted tothe slide through the same rack and pinion and shaft, substantially asdescribed.

13. The combination of an instrument, a rack bar, a pinion engaging saidrack bar, a shaft carrying said pinion and provided with coarse motionoperating devices, of a slowmotion device consisting essentially of arotatable part carried by said shaft and adapted to rotate with it, saidpart being provided with one or more spiral ribs or grooves, and, anendwise movable part engaging said spiral ribs or grooves and adapted torotate said rotatable part and its shaft, substantially as described. a

In testimony whereoflafiix mysignature in presence of two witnesses.

HIRAM G. SEDGWICK.

Witnesses:

CHARLES D. DAVIS, WM. R. DAVIS.

